Apparatus for the continuous casting of molten metal



Oct. 3, 1967 P. K. BEEMER 3,344,847

APPARATUS FOR THE CONTINUOUS CASTING OF MOLTEN METAL Filed March 14,1966 5 Sheets-Sheet 1 N INVENTOR PAUL K. BEEMER ATTORNEYS Oct. 3, 1967K, BEEMER 3,344,847

APPARATUS FOR THE CONTINUOUS CASTING OF MOLTEN METAL Filed March 14,1966 5 Sheets-Sheet 2 PREHEATING STATION TUNDISH TUNDISH CLEANINGSTATION INVENTOR.

PAUL K. BEEMER R I WM' ZMW ATTORNEYS Oct. 3, 1967 P. K. BEEMER 3,344,847

APPARATUS FOR THE CONTINUOUS CASTING OF MOLTEN METAL Filed March 14,1966 5 Sheets-Sheet 3 INVENTOR. PAUL K. BEEMER mm, M'

ATTORNEYS Oct. 3, 1967 P. K. BEEMER 3,344,347

APPARATUS FOR THE CONTINUOUS CASTING OF MOLTEN METAL Filed March 14,1966 5 Sheets-Sheet 4 b PAUL K. BEEMER 7 7 56uBY M M? WW ATTORNEYS Oct.3, 1967 P. K. BEEMER 3,344,847

APPARATUS FOR THE CONTINUOUS CASTING OF MOLTEN METAL Filed March 14,1966 5 Sheets-Sheet 5 52 FIG 9 INVENTOR.

PAUL K. BEEMER BY M54), ATTORNEYS United States Patent 3,344,847 7APPARATUS FOR THE CONTINUOUS CASTING OF MOLTEN METAL Paul K. Beemer,Laguna Beach, Calif., assignor, by mesne assignments, to UnitedEngineering and Foundry Company, Pittsburgh, Pa., a corporation ofPennsylvania Filed Mar. 14, 1966, Ser. No. 534,185 2 Claims. (Cl.164-281) This invention relates to the continuous casting of moltenmetal such as steel. Continuous casting is the production of a castingmany times the length of the mold in which it is produced.

The invention more particularly relates to a method and apparatus whichprovides great flexibility and versatility in the casting process. Theflexibility and versatility resides primarily in the use,interchangeably on the same casting machine, of:

1) One or a sequence of ladles (independently or simultaneously) inassociation with two single-stream tundish boxes and two molds; and

(2) One or a sequence of ladles in association with one multiple-streamtundish box and a plurality of molds.

Thus the method and apparatus provides for the selection, in a singlepiece of equipment, of several distinct modes of operation which havedifferent and distinct utility. And, in addition, the equipment makespossible longer uninterrupted operation since it may be used forsequence casting, i.e. casting a plurality of heats or ladles into onecontinuous strand, to the extent that heat timing and scheduling willallow.

In the continuous casting operation there is always a possibility thatmetallurgical defects such as slag fragments, or process failures suchas mold coolant or lubrication disturbances, may cause a breakout. Abreakout is a break in the solidified outer portion of the cast baradjacent the still molten or liquid central portion of the bar in themold. Thus the molten interior is allowed to penetrate the hardenedouter portion and the continuity of the strand is interrupted. Theequipment mustbe shut down for timeconsuming clean-up and subsequentstart-up operations. Because furnace production is carefully timed tosupply the normal casting capacity of the casting equipment and furnaceheats can be kept in a molten state only a limited time (roughly 40-50minutes), a breakout may result in the loss of several heats.

The present invention assures continuous operation (and casting of thefurnace heats as they are produced) in spite of a breakout. Thus itsignificantly reduces the economic consequences of a breakout. Thereduction is made possible by the provision of at least two strands. Twostrand capability is derived from the provision of two molds, each withindependently operable bar or strand withdrawal apparatus, and a set ofinterchangeable tundish boxes which includes one double-stream tundishbox and two single-stream tundish boxes.

The pair of molds and set of tundish boxes makes the two interchangeablemodes of operation referred to above possible. One mode is independentoperation of both molds from separate tundish boxes and ladles. Thus themode consists of two complete and independent strand forming meansoperating side-by-side. If each strand is cast at a rate sufiicient touse all of the molten metal in its respective ladle before it hardens inthe ladle, this mode is the most efiicient procedure because it requiresonly one starting bar and produces only one end crop per heat or ladle.On the other hand, the drawing speed required is high which increasesthe chance of breakout and requires greater control of the processparameters such as the coolant temperature, rate of mold oscillation,and mold lubrication.

The second mode is the operation of both molds from 3,344,847 PatentedOct. 3, 1967 one double-stream tundish box and one ladle. This mode hasthe advantage of requiring only one ladle carrier and only one tundishbox. It permits lower drawing speeds and therefore reduces the risk ofbreakout and is less sensitive to process parameters. In case of abreakout,

the discharge nozzle feeding the affected mold can be plugged and theremainder of the heat can be used without interruption in formation ofthe other strand.

Depending on variable factors in day-to-day operation,

'such as labor, purity of the molten metal, availability of 'rawmaterials, and production demand, it may be 'desirafter described, itwill be understood that tundishes can be placed either in thearrangement of FIG. 3 or in the arrangement of FIG. 8, on the'samemachine, as desired. It will be readily clear to those skilled in theart that for that matter, the tundishes of FIG. 3 can both be -tundishes just like that of FIG. 8 but with one of their discharge orificesplugged.

As an additional advantage, the apparatus has the capability ofpermitting sequence casting, to the extent that heat timing andscheduling will allow, since it permits ladle changeover in less timethan it takes the tundish box to empty. Sequence casting requires onlyone starting bar and produces only one end crop per strand sequence,

and accordingly represents an additional advantage.

Apparatus for the continuous casting of molten metal was first disclosedin 1865 in United States Patent No.

49,053, issued to Sir Henry Bessemer. Since then, the art has developedconsiderably, particularly as related to the continuous casting ofnon-ferrous metals such as aluminum and copper.v In roughly the last tenyears considerable effort has been directed to the continuous casting offerrous metals, particularly in Europe and Asia. The continuous castingof steel in the United States was begun, on a production level, in about1962.

The development and state of the art of continuous casting ofnon-ferrous aswell as ferrous metals is well stated in a 1964publication of the Association of Iron and Steel Engineers, Pittsburgh,Pa., entitled Continuous and Pressure Casting.

The continuous casting of ferrous metals is generally moredifiicultthanthe continuous casting of non-ferrous metals. As compared to non-ferrousmetals, ferrous metals have a higher melting point, a higher specificheat, and a lower rate of thermal conductivity.-Accordingly, thecontinuous casting of ferrous metals is more sensitive than thecontinuous casting of non-ferrous metals. because of the highertemperaturesrequired to maintain the metal in a molten state, and thedeeper liquid zone in the mold due to the lower rate of thermalconductivity. Methods and apparaus for continuous casting of non-ferrousmetals, accordingly, must be more versatile and flexible in the rate atwhich molten metal is used from a ladle or ladles and withdrawn from themold or molds to avoid hardening in the ladles or tundish boxes and toproduce a homogeneous, sound, and continuous bar. a a a Previousattempts to provide sequence capability are disclosed inl'unghans,British Patent 704,620, published Feb. 24, 1954 and in Namy, UnitedStates Patent No. 3,218,682, filed Mar. 19, 1963 and issued Nov. 23,1965. In the case of the Junghans apparatus, changeover. from one ladleto another is made by reciprocally moving the ladles and supportingracks on straight parallel tracks. Some interruption in flow of moltenmetal into the mold 2 occurs. In the Namy apparatus, changeover is madeby pivoting the tundish boxes while the ladles remain sta tionary nextto one another. The pivoting of the tundish .boxes,-though satisfactoryfor the immediate objective of "strand continuous casting apparatuswhich canbe selectively used in either the independent mode orsimultaneous mode described above. 7 It is another object of the presentinvention to provide ,a method and apparatus for the continuous castingof molten metal which is versatile and flexible in the rate with whichthe molten metal may be used or formed into bars. a

It is a further object to provide a method and apparatus for thecontinuous casting of molten metal which allowsa changeover ortransition from one heat or ladle of molten metal to another ladlewithout interrupting flow into the mold, to thereby produce a continuouscasting formed integrally from the two heats or ladles withoutinterruption.

It is a further object to provide a method and apparatus foraccomplishing an uninterrupted transition or changeover, as describedabove, without restricting subsequent movement of the tundish box orboxes from divergent and distinct cleaning and preheating stations.

It is a further object to provide apparatus for the continuous castingof molten metal which includes and is characterized by a turretconsisting of one or more ladle carriers mounted for pivotal movementabout a vertical axis and adapted to receive and support a ladletherein.

It is a further object to provide apparatus for the continuous castingof molten metal, consisting of a turret as described above, a pair ofmolds, means for continuously withdrawing solidified metal from themolds, and a set of tundish boxes for serving the molds and the ladles,to thereby provide great flexibility and versatility in the rate ofdischarge of molten metal from the molds and allow uninterruptedtransition from one ladle to another.

Each of the above objects is fulfilled by the embodiment 7 shown in thedrawings wherein:

FIG. 1 is a side or profile view of the continuous casting apparatus;

FIG. 2 is a top view of the apparatus shown in FIG. I with the ladlesremoved and with a portion of the ladle carriers broken away;

. FIG. 3 is an enlarged top view of the tundish boxes, overflow system,and ingot mold shown in FIG. 2;

FIG. 4 is a front view of the tundish boxes, overflow system, and ingotmold shown in FIG. 3 and, in addition, shows two molds (one in section)and the tundish box mounting track;

FIG. 5 is a top view of the turret which characterizes the presentinvention. It shows the ladle carriers, the ladle carrier track, thetundish mounting track, and means for pivotally moving the ladlecarriers about a vertical axis;

FIG. 6 is a side view of the apparatus of FIG. 5 and shows a ladle aboutto be seated on the ladle carrier. FIG. 6 also shows the drive means forpivotally moving the ladle carriers about a vertical axis and it showsthe ladle carrier locking mechanism;

FIG. 7 is a fragmentary view taken on the line 77 of FIG. 6 and showsthesolenoid actuated release for the 'molds; and

4 a FIG. 9 is a side view of the tundish box shown in FIG. 8 and showsthe means for mounting the tundish box to the tundish box track and therelationship between'the ladle, tundish box and mold.

The invention, described generally and in detail below,

comprises apparatus for the continuous casting of molten metal andincludes a mold, means for continuously withdrawing solidified metalfrom the mold, a tundish box disposed above the mold,'and adapted toreceive molten metal from the ladle and discharge the molten metal intothe mold, a ladle carrier adapted to support the, ladle, and meansmounting the ladle carrier for pivotal move- 'mentabout a vertical axisin a plane above the tundish boxes and the mold, to thereby allowpositioning of the ladle over the tundish box for discharge into thetundish box.

V The invention may be generally understood with reference to FIG. 1.The continuous casting apparatus includes a pair of ladle carriers 11aand 11b mounted for independent pivotal movement about the vertical axis12 of center post 13. Each of the ladle carriers is adapted to receiveand support a ladle 14. A tundish box 15a is mounted below the planedefined by arcuate movement of ladle 14 (with the pivotal movement ofladle carrier 11a).

Tundish box 15a is also mounted for arcuate movement.

.. carrier 11a. Molten metal is then discharged from ladle 14 by openingthe ladle stopper as provided for by stopper apparatus 23. A stream ofmolten metal M flows from .ladle 14 into tundish box 15a which serves asa reservoir. The stream M is discharged from tundish box 15a into mold16a where it solidifies. Mold 16a may be oscillated and lubricated toavoid the formation of a bond between the solidified metal and the mold.Solidified metal isc'ontinuously withdrawn from mold 16a by means ofrollers 21 and 22. After passing through rollers 22, the solidi-'fielgi1 metal is sheared to appropriate length on a runout ta e.

Though not described immediately above, the casting which may receiveoverflow, if any, from tundish boxes 15a and 15b and a launder 24 whichis capable of intercepting the discharge from the tundish boxes. Theoverflow system includes two laterally movable chutes 25a and 25b, anoverflow basin 26, a basin discharge chute 27, and an ingot mold 28.Launders 24a and 24b (see FIGS. 2 and 3) are pivotally mounted to basin26 below tundish boxes 15 and are pivotable to intercept the discharge(see 24b, FIG. 3) or avoid the discharge (see 24a, FIG. 3) from thetundish boxes 15 as may be-desired. Launders 24 are used at start-upuntil the discharge from the tundish boxes becomes clear.

Molds 16a and 1611' are cooled by means of coolant 29 circulated fromreservoir 30 through mold cavities 31.

The apparatus also includes means for initially withdrawing thesolidified bar from the mold at start-up. The initial withdrawal means,shown 'in FIGS. 1 and 2, dummy. bars 32a and 32b mounted for storage onwheels 33a and 33b. Dummy bars 32a and 32b are fed through molds 16a and16b respectively, and through rollers 21 -a nd 22.'The trailing end isleft in niold'16 and the initial discharge of molten metal into mold 16solidifies about dummy bar 32. The dummy bar is then withdrawn and leadsthe solidified metal through rollers 21 and rollers 22 for eventualexposure. After initial exposure, dummy bars 32a and 32b are no longerused and are stored as shown in FIG. 1.

The apparatus described is mounted on a frame 34 which supports turret35 and operating platform 36 above floor level 37.

With the foregoing general description of the apparatus and itsoperation, the specific design of the various members may beconveniently understood.

The turret which characterizes the present invention appears in FIGS.1-6. Ladle carriers 11a and 11b are pivotally mounted to center post 13and retained in place by means of cap 38. A bearing 39 (shown in FIG. 6)insures smooth pivotal movement of arms 11a and 11b about center post13.

Ladle track 40 is disposed concentrically about vertical axis 12 andcenter post 13 and is welded to turret platform 41. Track 40 is engagedby wheels 42 which are mounted for rotation about a radial axis passingthrough vertical axis 12. Two wheels 42 are provided for each ladlecarrier as best seen in FIG. 5. With reference to FIGS. 5 and 6, wheels42 are mounted to ladle carriers 11a and 11b by means of wheel mountingbrackets 43. Wheel mounting brackets 43 locate wheel pin 44 radially ofvertical axis 12 and center post 13. Thus ladle carriers 11a and 11b areindependently pivotally mounted for 360 movement about vertical axis 12as wheels 42 engage track 40.

As best seen in FIGS. 3, 8 and 9, tundish boxes 15a and 15b are mountedon turret platform 41 by means of tundish track 45. Tundish track 45 iswelded to turret platform 41 concentrically with vertical axis 12. Itincludes an upper track 46, and a lower track 47. Tundish boxes 15a and15b are mounted to tundish box arms 48a and 48b which may telescope. Anupper pair of tundish box wheels 49 is mounted to arm bracket 50 forrotation about a vertical axis. A second upper pair 51 is mounted tobracket 50 for rotation about a radial axis and a lower set 52 ismounted to bracket 50a for rotation about a vertical axis. As best seenin FIG. 9, upper wheels 49 engage the inner vertical edge of track 46.Wheels 51 engage the upper horizontal surface of track 46. Lower wheels52 engage the outer vertical surface of track 47.

Thus tundish boxes 15a and 15b are hung on track 45 and may be arcuatelymoved about vertical axis 12. The arcuate movement of tundish boxes 15aand 15b provides for great flexibility and widely divergent tundish boxstations. Thus tundish boxes 15a and 15b may be disposed at a productionstation, as shown in FIGS. 2, and 3, or in a preheat or cleaning stationnoted in FIG. 2.

Ladle carriers 11a and 11b are provided with a drive mechanism andlocking means'shown in FIGS. 5, 6 and 7. The ladle carrier drive meansincludes a motor and gear reducer 53a and 53b mounted to lade carriers11a and 11b respectively. Output shafts 54a and 54b extend verticallythrough ladle carriers 11a and 11b respectively and are rotatablymounted thereto by means of bearings 55a and 55b. Spur gears 56a and 56bare keyed to the lower end of output shafts 54a and 54b respectively andengage internal gear 57.

Internal gear 57 is welded to turret platform 41 and disposedconcentrically about vertical axis 12. Thus spur gears 56a and 56b, whendriven by motors 53a and 53b respectively, engage internal gear 57 andcause independent pivotal movement of ladle carriers 11a and 11b aboutcenter post 13.

Ladle carrier locking means is provided to lock ladle carriers 11a and11b in two production stations and one loading station. The lockingmeans consists of a pair of gussets 58 whim are mounted on the innerside ofladle track 40 at three circumferentially spaced points. Gussets58 define two production stations in proximity to tundish boxes 15a and15b (FIG. 2) and one loading station substantially opposite theproduction stations. Ladle carriers 11a and 11b are provided with alatch member 59a and 59b respectively. Latch members 59a and 5% arepivotally mounted by means of pins 60a and 60b. Due to theirconfiguration and the location of pins 60a and 60b, latch members 59aand 59b are urged by gravity into contact with the inside face of ladlecarrier track 40. The naturally thanging position of latch members 59aand 59b is shown in FIG. 6 with the lower vertical edge 61 thereof incontact with the inner vertical surface of track 40.

Thus as ladle carriers 11 are pivoted about center post 13, edge 61 oflatch member 59 rides in contact with track 40 until urged inwardly bygussets 58. When latch member 59 rides over the leading gusset 58 itseats itself in the space between the pair of gussets and locks theladle carrier 11. As ladle carriers 11 are pivoted through 360 on track40, the locking mechanism serves to automatically lock each of the ladlecarriers at two production stations and one loading station.

Ladle carriers 11a and 11b are released by means of a solenoid 62provided in association with each station. As shown in FIG. 7, solenoid62 includes solenoid plunger 63 which extends radially through track 40.Solenoid plunger 63 has a withdrawn position in which it is coincidentor flush with the inner vertical surface of track 40 as shown in FIG. 7.When actuated, solenoid plunger 63 has a stroke which pushes latchmember 59 out of locking engagement with gussets 58 to thereby releasethe locking member and ladle carrier.

The overflow system appears in detail in FIGS. 3 and 4. It includes apair of chutes 25a and 25b, an overflow basin 26, an overflow basinchute 27 and an ingot mold 28. Chutes 25a and 25b may be positionedlongitudinally of overflow basin 26 by means of chute brackets 64 whichaccept vertical pins (not shown) extending downwardly from chutes 25aand 25b. Thus chutes 25a and 251; may be positioned to catch tundishoverflow, as shown in FIGS. 3 and 4. The overflow system insurescomplete utilization (though used in an ingot mold and not in acontinuous operation) of molten metal and provides for additionalflexibility and versatility in the use of the apparatus.

A double-stream tundish box 65 is shown in FIG. 8. It is mounted thesame as tundish boxes 15a and 15b and has suflicient width to serve twomolds. For that purpose it contains two spaced discharge orifices 66aand 66b which are spaced a distance equal to the spacing of molds 16aand 161). Thus double-stream tundish box 65 directs dischargesimultaneously into molds 16a and 16b.

As shown in FIGS. 1 and 4, mold 16 is preferably formed with arefractory inner liner 70.

Tundish boxes 15a and 1512 as well as the double-stream tundish box 65are formed with a brick inner lining 71 and are provided with overflowtroughs 72 as shown particularly in FIGS. 1 and 3. The overflow troughs72 may be plugged as desired.

The apparatus described in detail above is especially versatile andflexible in its use. It provides means for continuously casting moltenmetal according to a number of related novel methods. Thus, as describedpreviously, the apparatus may be used with one or a sequence of ladlescontaining molten metal and one or a pair of tundish boxes.

More particularly, one method of continuously casting molten metalcomprises filling ladle 14 with molten metal, arcuately moving the ladleabout vertical axis 12 on ladle carrier 11 into a position above atundish box 15 and mold 16, discharging the molten metal from ladle 14into tundish box 15 and from tundish box 15 into mold 16, and coolingthe molten metal in the mold 16 and continuously withdrawing thesolidified metal from mold 16 by means of rollers 21 and 22. A series ofladles 14 may be sequentially positioned above tundish box 15 to providea continuous discharge of molten metal from tundish box 15, the moltenmetal having been contained in both of 7 the ladies. Thus a continuouslycast from aplurality of ladles.

The uninterrupted transition from one ladle to another is made byarcuately moving the first ladle about vertical axis 12 from itsdischarge position above tundish box 15 and arcuately moving a secondladle about vertical axis 12 into the position =formerly assumed by thefirst ladle and then discharging molten metal from the second ladle,into tundish box 15 during the duration of the first ladle stream. Theterm first ladle stream refers to the discharge from tundish box 15 intomold 16 of molten metal from the first ladle. Thus, although atransition from one ladle to another is made, the discharge from tundishbox 15 is bar may be derived continuous due to its function as areservoir, and the critical timing with respect to the discharge tromthe second ladle.

Additional versatility is provided by a method for continuously castingmolten metal which utilizes two tundish boxes and two molds. The methodcomprises filling a ladle 14a with the molten metal, arcuately moving afirst ladle 14 about vertical axis 12 into a. position above a firsttundish box 15a and mold 16a, discharging the molten metal from thefirst ladle into first tundish box 15a and mold 16a, cooling the moltenmetal in mold 16a and continuously withdrawing it there-from, andconcurrently arcuately moving a second ladle 14 about vertical axis 12into a position above a second tundish box 15b and mold 16b, andsimultaneously discharging the molten metal from the second ladle intosecond tundish box 15b, mold 16b, and withdrawing solidified metaltherefrom.

An additional method for continuously casting the molten metal ischaracterized by double-stream tundish box 65. The method comprisesfilling ladle 14 with molten metal, arcuately moving ladle 14 aboutvertical axis 12 into a position above tundish box 65 and a pair ofspaced molds 16a and 16b, discharging molten metal from ladle 14 intotundish box 65 and from tundish box 65 simultaneously through dischargeorifices 66a and 66b into molds 16a and 16b, and cooling the moltenmetal in each of the molds 16a and 16b and simultaneously withdrawingsolidified metal therefrom.

' And finally, the double-stream tundish box may be used in associationwith a sequence or plurality of ladles for continuous casting. Such amethod comprises filling a plurality of ladles 14 with molten metal,arcuately moving a first ladle about vertical axis 12 into a positionabove tundish box 65 and molds 16a and 16b, discharging the molten metalfrom the first ladle into tundish box 65 and from tundish box 65simultaneously into each of the molds 16a and 16b to thereby define aplurality of first ladle streams, cooling the molten metal in each ofthe molds 16a and 16b and continuously withdrawing solidified metalsimultaneously from each of the molds, arcuatelymoving the first ladleabout vertical axis 12 out of its discharge position above tundish box65, arcuately moving a second ladle about vertical axis 12 into adischarge position above tundish box 65, and discharging molten metalfrom the second ladle into tundish box 65 during the duration of thefirst ladle stream to thereby provide for an uninterrupted transitionfrom one ladle to another.

The various methods described above allow a variation of the rate of useof the molten metal. Thus with metals requiring slow casting speeds,double-stream production may be utilized to form bars and thereby usethe molten metal before it has any opportunity to solidify in the ladle.The other methods described may be utilized to vary the rate of use ofmolten metal to an even greater extent. 7

Moreover, the method of changing over from one ladle to another,characterized by arcuate movement of ladles 14 about vertical axis 12,provides for truly continuous casting within the limits referred toabove. Thus a'bar of indefinite length may be produced from a pluralityof heats or ladles.

The formation of a solidified steel bar by the use of the aboveapparatus and methods is accomplished at a rate of withdrawal from molds16 of about eight to ten feet per minute. The rate of withdrawal mayvary considerably, however, as a function of the cooling characteristicsof the metal being cast and the length of time available to use upmolten metal in the ladle to thereby avoid premature solidification inthe ladle. Molds 16 are preferably formed with a mold cavity of 4 /2inches square.

Ladles 14 are preferably filled with twelve to fourteen tons of moltenmetal at the furnace and then moved into position on ladle carrier 11 bymeans of a crane hook 73 shown in FIG. 6. The arcuate movement of theladles is accomplished by the ladle carrier drive mechanism describedpreviously.

Upon completion of the casting process the hardened bar is cut by shear74 and placed on runout table 75.

Having thus described my invention, I claim:

1. Continuous casting apparatus comprising:

a plurality of independently operable spaced mold means for formingstrands of solidified metal;

a multiple-stream tundish box having a plurality of discharge openingsspaced to register with said spaced molds;

a plurality of single-stream tundish boxes, each of said single-streamtundish boxes having a single discharge opening therein;

means for mounting said tundish boxes and for selectivelyinterchangeably moving said tundish boxes into and out of a positionwith the discharge openings thereof in registry with said molds; and

means for discharging molten metal into said tundish boxes, includingladle carrier means mounted for pivotal movement about a vertical axisin a plane above said tundish boxes and said molds.

2. Apparatus for the continuous casting of molten metal comprising:

a plurality of spaced molds;

means for continuously withdrawing solidified metal from said molds;

a plurality of tundish boxes including a multiplestream tundish box anda single-stream tundish box; means mounting said tundish boxes abovesaid molds for independent a-rcuate movement about a vertical axis, intoand out of registry with said molds;

a plurality of ladle carriersg. means mounting said ladle carriers forindependent arcuate movement about said vertical axis; means forarcuately selectively moving said ladle carriers about said axis; and

means for locking said ladle carriers in registry over one of saidtundish boxes.

References Cited UNITED STATES PATENTS 272,683 2/1883 Hainsworth 2279 X284,005 8/1883 Hainsworth 2279 309,540 12/ 1884 Hainsworth 22-79 X3,273,208 9/1966 Greenberger 22-57.2

FOREIGN PATENTS 704,013 2/1965 Canada. 602,796 3/1960 Italy.

I. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner.

1. CONTINUOUS CASTING APPARATUS COMPRISING: A PLURALITY OF INDEPENDENTLYOPERABLE SPACED MOLD MEANS FOR FORMING STRANDS OF SOLIDIFIED METAL; AMULTIPLE-STREAM TUNDISH BOX HAVING A PLURALITY OF DISCHARGE OPENINGSSPACED TO REGISTER WITH SAID SPACED MOLDS; A PLURALITY OF SINGLE-STREAMTUNDISH BOXES, EACH OF SAID SINGLE-STREAM TUNDISH BOXES HAVING A SINGLEDISCHARGE OPENING THEREIN; MEANS FOR MOUNTING SAID TUNDISH BOXES AND FORSELECTIVELY INTERCHANGEABLY MOVING SAID TUNDISH BOXES INTO AND OUT OF APOSITION WITH THE DISCHARGE OPENINGS THEREOF IN REGISTRY WITH SAIDMOLDS; AND MEANS FOR DISCHARGING MOLTEN METAL INTO SAID TUNDISH BOXES,INCLUDING LADLE CARRIER MEANS MOUNTED FOR PIVOTAL MOVEMENT ABOUT AVERTICAL AXIS IN A PLANE ABOVE SAID TUNDISH BOXES AND SAID MOLDS.